When we didn't have much money, we had to be more resourceful.

resourceful 是由名词 resource（资源）加上后缀 -ful（充满...的）构成的形容词。resource 指"资源、办法"，-ful 表示"充满...的"，所以 resourceful 字面意思是"充满资源的"，引申为"足智多谋的、善于随机应变的"。